1. Field of the Invention
The present invention pertains to the art of refrigerators and, more particularly, to a system for controlling operating temperatures in a fresh food compartment, as well as in a specialty storage compartment provided within the fresh food compartment.
2. Discussion of the Prior Art
In the art of refrigerators, particularly household refrigerators, it is often desirable to create varying humidity and/or temperature storage zones to enhance the preservation of different food items. For instance, it is common to accommodate the storage requirements for certain food items, such as dairy products, meats, fruits and vegetables, by forming separately enclosed storage areas within a fresh food compartment. In most instances, these storage areas are designed to be maintained at temperatures which are different from the temperature of the remainder of the fresh food compartment.
In at least the case of fruits and vegetables, it is typically desirable to isolate these food items from direct contact with a flow of cooling air, especially any cold air flowing into the fresh food compartment from a freezer compartment of the refrigerator, mainly because this cold air can be fairly dry. Therefore, in order to isolate the fruits and vegetables from the desiccating effects of the cold air so as to maintain the moisture content of the fruits and vegetables, it has heretofore been proposed to provide a specialized storage receptacle, such as a crisper, within a refrigerator fresh food compartment. A crisper generally takes the form of a slidable bin which is sealed to maintain a relatively high humidity level, while the walls of the bin are chilled to establish a desirable temperature within the bin.
Many different food storage compartment designs have been proposed in the art in an attempt to establish and maintain effective humidity and temperature conditions within the compartment while attempting to avoid the development of condensation. However, there still exists a need for an improved control system for maintaining a desired humidity level, accurately regulating the temperature and minimizing the tendency for condensation within a specialty storage compartment provided in the fresh food compartment of a refrigerator.
The present invention is directed to a high performance refrigerator storage compartment system which is constructed to prevent the loss of humidity, provide an accurately controlled temperature environment and minimize the potential for condensation within a food storage receptacle. In accordance with the invention, the system includes an enclosure, which is mounted within a fresh food compartment of a refrigerator, and a food receptacle, preferably in the form of a bin or drawer, which is slidably mounted between a retracted position, wherein a food storage body portion of the receptacle is generally sealed within the enclosure, and an extended position, wherein the food receptacle is at least partially withdrawn from the enclosure to access the storage body.
In the most preferred form of the invention, the enclosure has an open frontal portion and is defined by inner and outer housings. More specifically, the inner housing is concentrically positioned within and internally spaced from the outer housing. Numerous vanes extend between the inner and outer housings and define flow passages or channels over, around and beneath the inner housing. A rear portion of the enclosure is subdivided by a partition wall into upper and lower plenum chambers. A fan is disposed in the partition wall to generate a flow of cooling air into the upper plenum chamber which is guided by the vanes to flow within the passages across a top wall of the inner housing, down along side walls thereof, along the bottom wall of the inner housing and to the lower plenum chamber. In this manner, the cooling air extends around the entire inner housing to establish a uniform, accurate temperature for the food storage receptacle.
Although the preferred form of the invention recirculates a majority of the air flow in order to ensure a minimal temperature gradient through the recirculated air stream, the outer housing is formed with an intake opening which fluidly communicates the freezer compartment of the refrigerator with the interior of the enclosure, while an exhaust opening also leads from the enclosure. At least one temperature sensor is preferably provided to sense the temperature in the enclosure for use in controlling the flow of cold air from the freezer compartment, in combination with controls provided at the front of the bin.
The present invention is particularly directed to a system for controlling the air temperature in not only the fresh food compartment, but particularly the ambient temperature in the receptacle and enclosure of the high performance food storage arrangement of the invention. The control system is responsive to sensed fresh food compartment cooling air inlet temperature, established settings for the high performance food storage system, and a sensed temperature within the food storage system, along with switches which indicate an opening state of the receptacle of the storage system and the door of the fresh food compartment. The control system not only regulates the main refrigeration components such as the compressor and defrost heater, but controls an auto damper for regulating the main air flow into the fresh food compartment, a bias heater associated with the auto damper, a display preferably provided as part of the food storage system and both a damper and a fan for controlling the amount of air circulated within the high performance food storage system. The overall control system operates to maintain a desired ambient temperature condition within the food storage system and also compensates for any diminishing available cooling air during periods wherein the air flow to the food storage system is cut-off.
Additional objects, features and advantages of the invention will become readily apparent from the following detailed description of a preferred embodiment of the invention when taken in conjunction with the drawings wherein like reference numerals refer to corresponding parts in the several views.